Sand-Filtration System For Improving Water Quality For Rural Community Water Supply

Abstract

The performance of a pilot sand filtration plant for a small town water supply was monitored over a seven month period to evaluate the physico-chemical and bacteriological quality of the filtered water from a system installed at Assin Praso in the Central Region of Ghana. The sand filter was effective in reducing turbidity by 44 - 83 %; colour by 33 - 75 %; iron by 39 - 84 % and organic matter by 66 - 80 %. The reductions in the faecal and total coliforms of the filtered water were 34 - 95 % and 50 - 92 %, respectively. However, mean levels of the quality parameters of the filtered water exceeded the WHO guidelines for drinking waters. The filtration system worked efficiently during the dry season (March - April), but the efficiency declined during the rainy season (May – August). Post filtration disinfection is therefore recommended to ensure the potability of the sand-filtered water. For small or rural community water supply system without addition of chemicals, the perfo-rmance of the sand filtration system could be improved by close supervision of the operations, especially protection of the water-body around the intake point.

Journal of Applied Science and Technology Vol. 12 (1&2) 2007: pp. 98-104